Contacting early is probably a very good sign for most breeders. It shows that you've really thought of getting a pup from that breeder and you're willing to wait for the right one. I'd look it this way: If the breeder contacted you back saying you should have contacted when she actually has pups, you should really find someone else. Getting to know each other before you are in a situation there is an actual cute puppy (that can make most people forget why this breeder and why that puppy) is really for future pup's best interest. The breeder is the one to spent the most time with the pups and gets to know their temperaments and other qualities and if she knows you well as you've formed that relationship early she can help you to pick a puppy that fits best your home, any possible type of training you have in mind etc...

I got my second dog (who now lives with my ex) from the same breeder than the first one and it was so easy and the puppy was amazing fit. Nuttu (older one) can be a real bitch sometimes so it was good that we had had contact for the whole four years so she knew me and also my dog's temperament so she could easily recommend a pup with clearly mellower and more human oriented temperament and I think that made a real difference that I never had to be worried of the girls getting along when the younger one matured.

Also, having a good relationship with the breeder before the pup helps if there are any proplems after you have the pup. You already have formed good communication so it'll be easier to get your breeders help and support, like I had when my younger dog needed a knee surgery when she was only four months old.

Early makes sense as you never know when the breeder might breed. It also gets you near the front of the puppy buyer line. As for the questionnaire, more isn't a bad thing. However, be aware that by saying a lot you can also bring things up the breeder might think twice about. Not saying that you should hide anything, just that some people tend to read into things when there is a lot said. Personally though, I'd like it. I'm a bit verbally excessive at times too